Electrical control system



' Nov. 29, 1932. D POTTER 1,889,003

ELECTRICAL CONTROL SYS TEM Filed May 16. 1929 2 Sheets-Sheet 1 ATTORN EYS NOV. 29, 1932. D POTTER 1,889,003

ELECTRICAL CONTROL SYSTEM Filed May 16, 1929 2 Sheets-Sheet 2 I 4 2 66 (7 0 g 5' /02-,2n W 90 (F: O

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ATTORNEYS Patented Nov. 29, 1932 UNKTE =arns not FREDERICK D. POTTER, OF LINDEN, NEW JERSEY ELECTRICAL CONTROL SYSTEM Application filed May 16, 1929. Serial No. 363,423.

l l steam heat boilers or furnaces, hot air and hot water furnaces and the like.

The invention ordinarily makes use of an electrical thermostat having contacts for A higher and lower temperatures and means responsive to temperature change for contact ing therewith.

' The control system may include one or more draft regulators for the boiler or furnace for example a draft check or damper l 1 between the combustion chamber and the flue,

and an ash pit draft below the grade.

Such draft regulators are preferably so combined that both the draft check and draft will be operable by single thermostat, the

. draft check being closed as the draft is opened and vice versa.

The electrical operating units for draft check and draft may be located at diflerent points with respect to the furnacey'or they may be brought together at a common point and may be combined into a single unit.

The invention also contemplates the mounting of one of the said units upon the ordinary steam pressure control lever of a steam heating furnace and combining in a mechanical sense certain of the elements of the pressure control and electrical control.

The invention includes novel features of construction of the electrical operating units and of their connection with one another and with the thermostat; also the provision of a switch or switches of novel construction arranged in novel relation to the other elements of the electrical operating unit or units and thermostat. I

The draft check is preferably although not necessarily formed as a casing or housing provided with a plurality of pivotal slats or shutters linked together and adapted to be connected to one branch of a stack pipe T placed between the furnace and the flue. Various other details are included in the invention which will be hereinafter fully described and claimed.

Reference is hereby made to the accompanying drawings of which Figure l is a vertical section through a portion of a house showing a heater in the cellar with operating units attached thereto and a thermostat located in a room above.

Fig. 2 is a front elevation of a stack shutter housing with the lower portion in section to show the operating means.

Fig. 3 is a section taken on the line 3-3 of Fig. 2.

Fig. 4 is a vertical section through the ash pit draft control unit and through the ash pit door.

Fig. 5 is a section taken on the line 55 of Fig. 4.

Fig. 6 is a wiring diagram of the complete system of Fig. 1.

Fig. 7 is a side elevation of a heater with a modification of my invention applied thereto.

Fig. 8 is an enlarged vertical section of another modification.

In the drawings I have shown a shutter unit 10, comprising a frame or casing 12, open at the front and having at the rear an integral pipe 14 open at front and rear. This pipe is inserted into one branch of a T member 16 of a furnace stack pipe 18, as near as possible to the chimney flue 20. Another desirable location for the shutte is the wall of the chimney above the stack pipe opening as indicated in dot and dash lines Fig. l.

A number of shutter blades or slats 22 are pivotally mounted on adjustable cone point screws 24 threaded in the side walls of the casing 12 and held secure by lock nuts 26. A link 28 is attached to cars 30, on each of the shutter blades 22, which causes all of the blades to move in unison. A pulley 32 is secured to a pintle 33 projecting from one end of the center blade outside of the casing and is mounted on a cone point screw 24 threaded in a lug 25 on the casing 12.

An electrical operating unit 116 is mounted below the casing 12 within a housing 31, and comprises a tilting beam or lever 34 pivotally mounted on a rod 36, attached to the housing 31. Two mercoids 38 and 40 are mounted on said lever, as shown in Fig. 2.

A plunger 42 controlled by the solenoid 43,

is attached to one end 35 of the tilting beam 34, by a link 44. A. flexible cord or cable 46 is also attached to the end of the tilting beam 34. The cord 46 passes around the pulley 32 and has a weight 48 attached to its other end.

A tripping lever 50 pivotally mounted on a bearing 52 carried by housing 31 is normally held against a stop 54 by means of a spring 56. A notch 58 in the upper end of said lever 50 receives the right hand end of the tilting beam 34 when said end is in the raised position shown in Fig. 2.

An electro-magnet 60 is mounted on housing 31 adjacent the lever 50 with its pole piece 61 opposite a plate 51 on the lever 50. The end of the beam 34 remains in engagement with the notch 58 until the magnet 60 is energized. Energizing of said magnet causes the lever 50 to be moved slightly about its pivot which disengages the end of the beam 34 from the notch 58, allowing said beam to pivot in a clock-wise direction until it strikes a stop 39. The weight 48 and cord 46 cause the end 35 0f the beam 34 to be pulled upward.

Since the cord is wound around the pulley 32, which is fixed to the center shutter blade, said blade is thereby rotated into closed position. The other blades will also close simultaneously with the center blade since they are all connected together by the link 28.

The solenoid plunger 42 will be partly withdrawn from the solenoid 43 as the left end of the beam moves upward. When the solenoid 43 is energized the plunger is drawn downward and causes all parts to be restored to the position shown in Fig. 2.

Referring now to the control unit 82 for operating the ash pit draft, the usual heavy pivoted flap in the ash pit door is replaced by a plurality of pivotal shutters 7 0 as shown in Fig. 4, similar to those in the stack unit and connected together by a link 71. A. cord or chain 72 is connected to a lug 74 on the uppermost shutter and to one arm of a lever 7 8 fulcrumed on stud secured to housing 79. A link 86 connects the other arm 82 of the lever 78 to a plunger 90 in a solenoid 92.

A locking pin 94 in one arm of the lever 78 is adapted to engage a notch 95 in a vertically disposed lever 96 pivoted on a stud 98 secured to the housing 7 9. A spring 100, attached to the lever 96 and to a stud 102 on one wall of the housing 79 holds the lever 96 in such position that the notch 95 receives the pin 94 of the lever 78. The lever 96 is provided with a plate 104 which is attracted by a magnet 106 when said magnet is energized.

The above described parts operate as follows: When the magnet 106 is energized, the lever 96 is moved to the right from the position shown in 4 which disengages the pin 94 from the notch 95 in the lever 96, thereby causing the lever 7 8 to be moved about its fulcrum 80 and the ash pit draft shutters 70 to close by gravity.

When the solenoid 92 is energized the plunger 90 is drawn down and causes the various parts to take the positions shown in Fig. 4. The shutters 70 are then open as shown.

The magnet 106 is wired in parallel with the solenoid 43 between the mercoid 40 and one pole of the battery or source of potential, and the magnet 60 is in parallel with the solenoid 92 between the mercoid 38 and the same pole of the battery.

The energizing of the magnets 60 and 106 and solenoids 43 and 92, is controlled by means of the mercoids 38, 40 and thermostat 62. One side of the mercoid 38 is connected to the magnet 60 and solenoid 92 and the other side to the contact point 64 of the thermostat 62. The mercoid 40 is similarly connected with respect to magnet 106, solenoid 43 and contact point 66 of the thermostat.

The contact 64 represents a low predetermined temperature and the contact point 66 ahigh predetermined temperature.

The operation of the device is as follows: The movable member of the thermostat 62 will engage either of the contacts 64 or 66 according to the temperature within the room in which said thermostat is placed.

If the temperature in the room is normal, say 7 0, the thermostat will engage the contact 66, and the draft check apparatus will be in the position shown in Fig. 2. shutter blades 22 are open, which checks the draft, since air is drawn through the shutter to the flue and the ash pit draft shutters 70 are closed.

If, however, the temperature in the room in which the thermostat is located drops suiliciently to cause the thermostat element 62 to engage the contact 64, the magnet 60 and solenoid 92 will be energized. This causes the lever 50' to be withdrawn from the end of the beam 34 and the plunger 90 to be drawn downward which moves the lever 7 8 to the position of Fig. 4, the result being the shutter vanes 22 are closed by the action of weight 48, and ash pit shutter vanes 70 are opened by the lever 7 8.

With shutters 22 closed and ash pit shut ters 70 open the fire flares up, which raises the temperature in the room, thereby moving the thermostatic element 62 into con tact with the contact point 66 energizing the magnet 106 and solenoid 43. The plunger 42 is now pulled downward, the lever 96 withdrawn, and the draft check parts restored to the position shown in Fig. 2, while the ash pit shutters 70 are closed by the action of gravity.

It is to be observed that the circuit to the magnet 106 and solenoid 43 is broken immediately after such elements are energized, due

to the mercury in the mercoid 40 being moved out of contact with the contact points by the tipping of the beam 34. Similarly the cirunit to magnet and solenoid 92 is broken immediately after energization thereof, due to the mercury of mercoid 38 being moved out of contact with the contact points by the tipping in a reverse direction of the beam 34.

When one pair of contacts is out of the mercury in one mercoid, the other pair of contacts is in the mercury in the other mercoid.

It is to be noted that the housing 79 is shown as mounted on one end of the fulcrum bar 5 of the steam pressure control device. lVhile it may if desired be mounted indepent- 1y thereof on a fixed support, the arrangement shown is a desirable one. One end of the ful crum bar 6 is connected to the usual stack damper of the furnace. It is pivoted at 0 to a post d and is actuated by a diaphragm e which is responsive to the pressure of the generated steam. The housing 7 9 is mounted on the forward end of the bar Z2 and in no way affects the operation thereof, since the raising of said end of the bar 5 by the diaphragm 6 causes a pull on the cord or chain 7 2 which opens the draft shutters 70.

Conversely. the descent of the said end of bar 6, as the steam pressure rises, permits the closing of shutters by action of gravity.

In Fig. 7 I have illustrated a modified structure in which the furnace piping comprises a T connection from the stack pipe to the shutter unit housing 111 and a pipe connection 114 from the ash pit to a housing 116 directly under and preferably integral with the shutter unit housing 111. A shutter 70 is mounted in the mouth of the housing 116 and actuated by the control unit 82 mounted above the shutter unit housing 116, which unit is the same as that shown in Fig. 4.

The housing 111 has a draft opening and a pivotal shutter for controlling the same. This shutter is operated by a control unit 116 which is the same as that shown in Fig. 2. The units 82 and 116 are operated by the thermostat 62 as previously described.

In the device of Fig. 8 the control unit 116 constructed and operated as previously de scribed actuates both the draft check and the ash pit draft, simultaneously opening the former and closing the latter and vice versa.

This is accomplished by mounting the draft check above the ash pit draft in a suitable housing as shown. This housing has three chambers, the upper one 11'? having a draft check inlet controlled by a pivotal shutter 118 and an outlet 14 connected to the stack pipe T 16 as in Fig. 3. The shutter has a pulley 32 around which passes the cord 46 for actuating the same.

The bottom chamber has a draft inlet Between the chambers 117 and 120 is a chamber 119 within which is the control unit 116 the same as previously described. This un1t causes a downward pull upon one end of the cord 46 when the arm 62 moves 1n response to a drop in temperature thereby closing the draft check shutter 118.

One end of the'cord 46 is connected to the shutter 121 as shown, and as the cord is actuated to close the draft check shutter 118, it simultaneously opens the shutter 121. This movement is brougth about by a downward movement of the solenoid plunger 42, Fig. 2.

When the thermostat arm 62 moves in response to a rise in temperature, thereby en ergizing the magnet 60, Fig. 2, the shutter 121 closes by gravity, pulling upon the cord 46 and opening the shutter 118. In other words the shutter 118 in addition to controlling the ash pit draft opening, performs the same function as the weight 48 of Figs. 2 and 3.

The wiring of the control unit 116 Fig. 8 is the same as in Fig. 6, except for the removal of the branch circuits leading to magnet 106 and solenoid 92.

I claim:

1. In an electrical control system, the combination of a thermostat and a pair of electromagnets in multiple with each other and in series with the thermostat, a heat regulator operable by one of said magnets, a second heat regulator, gravity means for operating the same, and means actuated by the other magnet for controlling the operation by gravity of the second heat regulator.

2. In an electrical control system, the com bination of a thermostat having contacts for higher and lower temperatures respectively, a pair of electromagnets in multiple with each other and in series with one of said contacts, another pair of electromagnets in multiple with each other and in'series with the other contact, heat regulators normally movable into a predetermined position and restorable by one of each pair of magnets, and means actuated by the other magnets for controlling the normal movement of the heat regulators.

3. In an electrical control system, the combination of a thermostat having contacts for higher and lower temperatures respectively.

a pair of electromagnets in multiple with each other and in series with one of said contacts, another pair of electromagnets in multiple with each other and in series with the other contact, heat regulators normally movable into a predetermined position and restorable by one of each pair of magnets, and means actuated by the other magnets for controlling the normal movement of the heat regulators, the magnets of each pair relating to the operation of different heat regulators.

4. In an electrical control system, the combination of a thermostat having contacts, an electromagnet in series with each of said contacts, a heat regulator normally movable into a predetermined position and restorable by one of said magnets, and means actuated by the other magnet for controlling the normal movement of the heat regulator.

5. In an electrical control system, the combination of a thermostat having contacts, an electromagnet in series with each of said contacts, draft controlling means including a lever, said draft controlling means being biased to move to one position thereof and being restorable to the other position thereof by one of said magnets, a detent retaining said lever in said second position and actuated by the other magnet to disengage said lever, and means operated by movement of said lever for controlling the circuits of said electromagnets.

6. In an electrical control system, the combination of thermostat having contacts for higher and lower temperatures respectively, a pair of electromagnets in series with one of said contacts, another pair of electromagnets in series with the other contact, heat regulators normally movable into a predetermined position and restorable by one of each pair of magnets, and means actuated by the other magnets for controlling the normal movement of the heat regulators.

7. In an electrical. control system, the combination of a thermostat having contacts for higher and lower temperatures respectively, a pair of electromagnets in series with one of said contacts, another pair of electromagnets in series with the other contact, heat regulators normally movable into predetermined position and restorable by one of each pair of magnets, detents retaining the regulators in the other position thereof and actuated by the other magnets for releasing the detents, and a switch. in series with each pair of magnets operated upon movement of said heat regulators to control the circuits of the electromagnets.

8. In a control system for heating apparatus, valvular combustion controlling means, means responsive to variations in conditions within said apparatus including a lever, a support carried by said lever, an actuating member movable on said support, a connection between said actuating member and said valvular combustion controlling means, electromagnetic means on said support for controlling the movement of said actuating member in opposite directions, and thermostatic means for controlling the operation of said electromagnetic means.

9. In a control system for heating apparatus, valvular combustion controlling means, means responsive to variations in conditions within said apparatus, a member carried by said responsive means and connected to said valvular combustion controlling means for actuating the same, said member being mounted to be actuated independently of said responsive means, a pair of electromagnetic devices for controlling the operation of said member in opposite directions, thermostatic circuit controlling means common to said electromagnetic devices, and a switch in series with each electromagnetic device operated automatically to open the circuit thereof after closing of said circuit by said thermostatic circuit controlling means.

10. In a control system for heating apparatus, a plurality of valvular draft controlling means, separate electromagnetic means for actuating each of said valvular draft controlling means, thermostatic means common to and controlling the circuits of said electromagnetic means in accordance with the temperature conditions at a point exteriorly of the heating apparatus, and means responsive to variations in conditions within the heating apparatus and supporting certain of said electromagnetic means for movement therewith to actuate the valvular draft con trolling means thereof in accordance with thermal conditions within and exteriorly of the apparatus.

11. In a control system for heating apparatus, a plurality of draft controlling means, separate electromagnetic means associated with each draft controlling means and in cluding components for controlling the operation thereof in both directions, and thermostatic means having contacts, one contact being in series with one component of each of said electromagnetic means for effecting operation of the plural draft controlling means in a certain direction, and the other contact being in series with another component of if each of said electromagnetic means for effecting operation of said plural draft controlling means in the opposite direction.

12. In an electrical control system for heat ing apparatus, a plurality of valvular draft I controlling means, a pair of electromagnetic devices associated with each draft controlling means for controlling the operation thereof in opposite direction, and a circuit controlling thermostat having a contact in series with one of the electromagnetic devices of each pair and another contact in series with the remaining electromagnetic devices of the pairs, said thermostat closing the circuit of one contact to control the movement of the plural draft controlling means to one position and closing the circuit of the other contact to control the movement of the plural draft controlling means to another position.

In testimony whereof, I have signed my name hereto.

FREDERICK D. POTTER. 

